
Beaverhead County, the City of Dillon, and the Town of Lima have been working with the Federal Emergency Management Agency (FEMA) and Montana Department of Natural Resources and Conservation (DNRC) to update and produce new floodplain maps for the Beaverhead River, Blacktail Deer Creek, Selway Slough and Junction Creek areas, and the Big Hole River.
Many of the existing floodplain maps are based on data from the late 1970s. Updated Flood Insurance Rate Maps will provide more accurate, current, and detailed data and mapping of flood risk areas. When finalized, the new maps could have effects on some property owners in mapped floodplains (see Floodplain FAQs page for more information).
View Preliminary Floodplain Maps
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View individual preliminary maps and reports here: Maps & Technical Reports
Get more information on floodplain designations referenced on the maps:
100-Year Floodplain
Floodway (within the 100-Year Floodplain)
500-Year Floodplain
Newly Mapped into a 100-Year Floodplain on the preliminary maps? See Low Cost Insurance Options
FEMA will open an official comment and appeal period on the maps (estimated mid 2021). For more information, see:
Appeal & Comment Fact Sheet
Appeal & Comment Form
Big Hole River Floodplain Maps
A flood study and floodplain maps for the Big Hole River were produced in 2015. These and other existing Big Hole River floodplain maps have been incorporated into Preliminary FEMA floodplain maps. They will go through an official 90 day comment and appeal period along with the rest of Beaverhead County's floodplain maps (estimated mid 2021). An informational meeting for the Big Hole River Preliminary maps was held on February 17, 2021. See below for more information.
Public Meetings
February 17, 2021 - The Big Hole Watershed Committee hosted a virtual meeting for landowners. View meeting materials: Presentation Slides Big Hole 100 year Floodplain Low Cost Insurance Options Comment and Appeal process.
January 21, 2021 - Beaverhead County, Dillon and Lima hosted a virtual public open house for landowners. View meeting materials: Presentation Recording (YouTube) Presentation Slides 100-Year Floodplain Floodway (within the 100-Year Floodplain) 500-Year Floodplain Low Cost Insurance Options Comment and Appeal Process
In 2019, Beaverhead County, Dillon, and Lima hosted two Public Open Houses to help property owners review the initial draft maps. The meetings were held: May 9, 2019 (in Dillon) and May 13, 2019 (in Lima). View materials from the 2019 meetings: Dillon Presentation Lima Presentation News Coverage 100-Year Floodplain Floodway 500-Year Floodplain Low Cost Insurance Options

Come back for more information
We will update this website with new, relevant information as this project progresses.